1. Field of the Invention
This invention relates to oil seals and in particular to oil seals for use in applications where a minimum radial force may be exerted on the bore and where the oil seal must be positively retained in the bore.
2. Description of the Prior Art
Prior art seals are known for use in applications such as rear crank shaft seals but have not been completely successful because their use results in leakage through the split area in spreading of the bearing cap-to-block interface which can cause a shortened bearing life; in some cases the prior art oil seals are subject to both of these disadvantages.
While O.D. sealing ribs are known (see U.S. Pat. No. 3,356,376), they are used with such an interference fit as to make the seal self-retaining in the bore, by exerting considerable force radially outwardly against the bore. Also, while locking beads are known per se (see U.S. Pat. Nos. 2,275,325, 2,857,179, 3,014,768, and 3,162,456), it is not known that the combination of the two, as in the present invention, will allow the O.D. sealing ribs to be designed with a reduction in the O.D. press-fit (force), while still maintaining an O.D. seal.